Wikilinks, title after pipe

Wikilinks can have one of the following forms:

[[https://example.org]]
[[https://example.org|title]]
[[name of page]]
[[name of page|title]]

With this version of wikilinks, the title comes after the pipe.

$ comrak -e wikilinks-title-after-pipe
[[https://example.org]]
$ comrak -e wikilinks-title-after-pipe
[[https://example.org|title]]
$ comrak -e wikilinks-title-after-pipe
[[Name of page]]
$ comrak -e wikilinks-title-after-pipe
[[Name of page|Title]]

HTML entities are recognized both in the name of page and in the link title.

$ comrak -e wikilinks-title-after-pipe
[[Geschütztes Leerzeichen|Über  ]]

Escaping characters is supported

$ comrak -e wikilinks-title-after-pipe
[[https://example.org|foo\[\]bar]]
$ comrak -e wikilinks-title-after-pipe
[[Name \[of\] page]]

Emphasis or other inline markdown is not supported

$ comrak -e wikilinks-title-after-pipe
[[Name _of_ page]]